The objective of this competitive renewal training grant application is to promote and support the successful career of pediatric hematologist-oncologists as physician-scientists in cancer research. There has been dramatic progress in biomedical research over the last 2 decades and it is now critical that this knowledge translate into new and better diagnostic and therapeutic advances for patients. Physician-scientists with strong research training play a critical role in this regard because of their dual training in research and clinical care. Paradoxically, the pool of such individuals has in fact decreased since the late 1990's. There is however indication that, as a result of initiatives taken by the NIH and other foundations, there is a progressive increase in "late bloomers" interested in a research career. This T32 grant application funded since 1991 by the NIH will now specifically target a group of such individuals with training in Pediatric Oncology. Twenty-eight faculty members at Childrens Hospital Los Angeles, the Keck School of Medicine of the University of Southern California and City of Hope, with more than $ 26 million in extramural funding and with a combined expertise in laboratory, clinical and population-based research, will contribute as mentors and faculty resourced. The proposed training program will provide a minimum of 2 years of training in cancer research to 2 new individuals each year, who will be selected from the Pediatric Hematology-Oncology Fellowship Program pt Childrens Hospital Los Angeles, a program with a solid record of training academic physicians. This training program will be conducted within the strong research and education environments of The Saban Research Institute of Childrens Hospital Los Angeles, the Norris Comprehensive Cancer Center of the Keck School of Medicine and City of Hope, which will provide the trainees with a comprehensive curriculum that combines formal classes, workshops and seminars, one-on-one education sessions, and access to more than 20 core facilities. It is anticipated that individuals who complete this training program will contribute to enhancing the pool of physician-scientists in the nation and most particularly in the field of pediatric cancer. RELEVANCE (See instructions): This training grant application focuses on addressing the critical issue of the shortage of physician-scientists in biomedical and translational research. It will focus on training individuals with MDs or MD/PhDs selected from a pool of participants in the Pediatric Hematology-Oncology Fellowship Program at CHLA/USC in laboratory or clinical/translational research. It is expected that this training program will contribute to replenishing the pool of physician-scientists in translational biomedical research.